Fix strict-aliasing warning in dlmalloc

This fixes the following warnings in dlmalloc seen with my gcc 4.6.

dlmalloc.c: In function 'malloc_bin_reloc':
dlmalloc.c:1493: warning: dereferencing pointer 'p' does break strict-aliasing rules
dlmalloc.c:1493: warning: dereferencing pointer 'p' does break strict-aliasing rules
dlmalloc.c:1490: note: initialized from here
dlmalloc.c:1493: note: initialized from here

This version is tested on avr32 arch boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/common/dlmalloc.c b/common/dlmalloc.c
index c645d73..1d7e527 100644
--- a/common/dlmalloc.c
+++ b/common/dlmalloc.c
@@ -1487,11 +1487,11 @@
 #ifdef CONFIG_NEEDS_MANUAL_RELOC
 void malloc_bin_reloc (void)
 {
-	unsigned long *p = (unsigned long *)(&av_[2]);
-	int i;
-	for (i=2; i<(sizeof(av_)/sizeof(mbinptr)); ++i) {
-		*p++ += gd->reloc_off;
-	}
+	mbinptr *p = &av_[2];
+	size_t i;
+
+	for (i = 2; i < ARRAY_SIZE(av_); ++i, ++p)
+		*p = (mbinptr)((ulong)*p + gd->reloc_off);
 }
 #endif